ASoC: omap-mcpdm: API to configure offset cancellation

The offset cancellation values can be different from board to board, even
on the same HW platform.
Provide a way for the machine drivers to configure the McPDM offset
cancellation.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/sound/soc/omap/omap-mcpdm.h b/sound/soc/omap/omap-mcpdm.h
index d23122a..de8cf26 100644
--- a/sound/soc/omap/omap-mcpdm.h
+++ b/sound/soc/omap/omap-mcpdm.h
@@ -92,4 +92,16 @@
 #define MCPDM_UP_THRES_MAX		0xF
 #define MCPDM_DN_THRES_MAX		0xF
 
+/*
+ * MCPDM_DN_OFFSET bit fields
+ */
+
+#define MCPDM_DN_OFST_RX1_EN		(1 << 0)
+#define MCPDM_DNOFST_RX1(x)		((x & 0x1f) << 1)
+#define MCPDM_DN_OFST_RX2_EN		(1 << 8)
+#define MCPDM_DNOFST_RX2(x)		((x & 0x1f) << 9)
+
+void omap_mcpdm_configure_dn_offsets(struct snd_soc_pcm_runtime *rtd,
+				    u8 rx1, u8 rx2);
+
 #endif	/* End of __OMAP_MCPDM_H__ */